Question

pH of `Ca(OH)_(2)` solution is 12. Millimoles of `Ca(OH)_(2)` present in 100mL of solution will be
A. 1
B. 0.5
C. 0.05
D. 5

Answer 1

Correct Answer - B
`pH =12`
`pOH =14-Ph =14-12=2`
`:. [OH^(-)]=10^(-2) M`
`:. [Ca(OH)_(2)]=0.5 xx 10^(-2) M`
( Assuming complete dissociation at this conc. )
Mili moles of `Ca(OH)_(2)` in solution
`=`MV (in mL )
`=0.5 xx 10^(-2) xx 100 =0.5 `